Co-founder of Kurashu and in charge of spreading the word on sake.
There are three ways that you can heat up sake, each with its own advantages and disadvantages.
1. Heating Up Sake In A Hot Water Bath
Most professional sake establishments will heat up sake by immersing it in hot water, ideally at 80°C. While there are machines that are made especially for that purpose they are probably a bit large and pricey for home use.
The easiest solution is simply heating up water in a pot. Get the water hot, but not boiling, and put a tokkuri (sake serving vessel) inside the hot water. Make sure that the flame is off, however, as you might otherwise break the tokkuri.
Ideally you will also have a food thermometer to measure the temperature of the water (ideal at 80°C) and then later the sake itself.
Not sure how high to heat your sake? Check out our guide to sake temperatures.